E-Commerce Unit V

UNIT-5
1. What is the compression method used in Multimedia?
· Sector-oriented disk Compression
· Backup or archive-oriented compression
· Graphics and video-oriented Compression
· Compression of data being transmitted over low-speed networks
2. What is the goal of data compression in action?
The goal of data compression is to make the size of the 100 –bit message
as close as possible to the 100 bits of underlying information.
3. What is the disadvantage of data compression?
The most obvious problem is the time to transfer that much data from
storage to the display. Nearly 30 Mb per second is enough to choke almost
any I/O port or data bus. Other problems include both storage and
processing.
4. What are the types of Compression Technique? Grief brief notes on them
Compression techniques can be divided into two major categories,
· Lossless Compression
· Lossy Compression
Lossless compression:
It means that a given set of data will undergo a loss of accuracy or
resolution after a cycle of compression and decompression.
Lossy Compression:
It produces compressed output that is exactly the same as the input.
5. Define Multiprocessing?
Multiprocessing is defined as the ability to support the concurrent
execution of several tasks on multiple processors. This implies that ability
to use more than one CPU for executing programs. The processors can be
tightly or loosely coupled.
6. Define multitasking?
Multitasking means that the server operating systems can run multiple
programs and give the illusion that they are running simultaneously by
switching control between them.
Two types of multitasking are used:
· Preemptive
· No preemptive
7. Define Multithreading?
Multithreading is a sophisticated and refers to the ability to support paths
of execution within a single address space. Older operating systems
achieve multitasking by creating multiple processes, which creates a great
deal of overhead.
8. Give brief notes about the types of storage technology?
Storage technology can be divided in to two types:
· Network-based (disk arrays)
· Desktop-based (CD-ROM)
Disk arrays:
Disk arrays store enormous of information and are becoming an important
storage technology for firewall servers and other electronic commerce
servers.
CD-ROM:
The preemptive desktop storage technology for electronic commerce
applications is CD-ROM.
9. What are the types of Desktop video conferencing?
There are three types of desktop video conferencing they are
· Plain Old Telephone lines(POTS)
· ISDN
· Internet
10. What is MBONE?
The MBONE is a virtual network that has been in existence since early
1992. The MBONE shares the same physical media as the internet. It uses
a network of routers is not for the faint of heart and is time consuming
because a lot of learning and fixing are involved.
11. Define SONET?
SONET, or Synchronous Optical NETwork, is a set of standards that
govern synchronous fiber optic data transmission at rates ranging from
51.8Mbps to 2.5Gbps.
12. How fast packet switching differs from the traditional circuit switching?
The fast packet switching differs from the traditional circuit switching in
the following three aspects
· Call set-up
· Traffic management
· Switching
13. Describe the benefits of Frame relay?
Frame relay has two benefits:
Speed:
It is no longer necessary to carryout error controls and corrections between
each node due to the improvements in transmission media.
Sharing costly bandwidth:
Frame relay allows users to share costly, high throughput channels over a
single access line, and it uses a “hubbing” approach to distribute traffic
over a wide area.
14. Describe the three functional levels in physical layer?
The physical layer can be divided into three functional levels:
· Transmission path
· Digital section
· Regenerator section
15. What are the four dimensions in mobile computing?
The four dimensions in mobile computing are,
· Wireless delivery technology and switching methods
· Mobile information access devices
· Mobile data internetworking standards and equipment
· Mobile computing based business applications
16. What are the categories of Radio based systems?
Radio based services can be grouped into two main categories:
· Land based
· Satellite based
17. What is palmtop?
Palmtop computers attempt to provide higher functionality and more
closely resemble what’s available in desktop computers. Palmtops called
personal organizers. It offer the combined functionality of a personal
organizer and communications terminal to provide access an applicationspecific
personal computer and communications terminal to provide
access to e-mail.
18. Specify the advantage of circuit-Switched Cellular transmission?
The advantage of circuit switched cellular transmission is that users should
be able to use a cellular modem as they would any modem. Because the
charge call is by the minute and also for set-up, cellular modems can be
more cost-effective when used to send large messages.
19. What is licensed broadband?
Licensed bandwidth allocation of 120 MHz in the 1850 MHz to 1990
MHz band represents a considerable amount of spectrum-by comparison,
the current cellular phone system, known as advanced mobile phone
system occupies only 50 MHz.
20. What is the application of unlicensed broadband?
These applications today are relegated to the industrial/scientific/medical
bands should make better use of the radio spectrum and allow for more
simultaneous users and better signal quality.

16 Marks
1. Explain about digital video and electronic commerce?
· Characteristics of Digital video
· Digital video compression/Decompression
· Types of Codecs
Hybrid
Software-based
· Three Hybrid standards
JPEG
MPEG II
2. Describe Desktop Video Processing?
Video on the desktop is a key element in turning a computer into a true
multimedia platform. However digital video isn’t what one would call a
“natural fit’ when it comes to desktop computers due to their inability to
process the compression and decompression of video satisfactorily.
· Desktop Video Hardware for playback and capture
· Video playback
· Video capture and Editing
· Desktop Video Application Software
· Apple’s Quick Time
· Microsoft’s video for Windows
3. Explain Desktop video conferencing? What are the types of Desktop video
Conferencing?
Desktop video conferencing is gaining momentum as a communications
tool. For many business users, face-to-face videoconferences are already a
common practice allowing distant colleagues to communicate without the
expense and inconvenience of traveling.
TYPES OF DESKTOP VIDEO CONFRENCING:
· Using POTS for video conferencing
· Using ISDN for video conferencing
· Using the internet for video conferencing
CU-SeeMe
MBONE
4. Describe the concept of Broadband background?
· Narrowband Versus Broadband Networks
· Integrated services Digital Network (ISDN)
· SONET and SDH
· BISDN Versus ATM
· Connectionless versus connection oriented networks
· Switching techniques
Call set-up
Traffic management
Switching
5. Explain about Asynchronous Transfer Mode (ATM)?
ATM is a high-speed, connection-oriented, cell based transmission scheme
that offers bandwidth on demand for voice, data and video telephony applications.
ATM networks are being created to switching technology voice, data and video
signals at multiples of 155 Mbps through multigigabit “hubbing devices”
Types of ATM traffic and switching:
· ATM Switching
· ATM cell structure
· ATM system Architecture
6. Give brief description about wireless delivery technology and switching methods?
· Radio-Based Systems
· Cellular Communications
Increasing Capability and widespread coverage for cordless
telephones
Decreasing cell size (micro cells) and power levels for
hand-held and vehicular cellular radio.
Specialized wireless data systems
· Wireless packet data networks
· Satellite networks
· Very small aperture terminals (VSATs)
· Paging and satellite Networks
· Infrared or Light-Based Mobile computing
7. Explain Mobile information access devices?
· Portable computers
· Hybrid pen computers
· Personal Digital Assistants (PDAs)
· Digital Assistants
· Personal communicators
· Palmtops
· Cellular modems and PCMIA adapters